Wireless communication between a base unit and one or more remote units is well known in the art. One well known method is Frequency Division Multiple Access (FDMA). In FDMA, the available electromagnetic communication spectrum is divided into a plurality of frequency channels. Communication between the base unit and one of the remote units is effected over one of the frequency channels. Communication between the base unit and a different remote unit is effected over a different frequency channel.
Time Division Multiple Access (TDMA) is also well known in the art. In TDMA communication, transmission between the base unit and a first remote unit is effected over a first "slice" in time. Transmission between the base unit and a second remote unit is effected over a second "slice" of time, different from the first "slice".
Finally, in Code Division Multiple Access (CDMA) the communication between a base unit and one or more remote units is accomplished through spread spectrum transmission over a frequency range wherein a unique Pseudo Noise (PN) code distinguishes the communication between a base unit and a first remote unit and a different code distinguishes the communication between the base unit and a different remote unit. There are several types of CDMA systems such as Direct Sequence, Frequency Hopping, and Time-Hopping. Direct Sequence spread spectrum systems encode a low rate data stream into a high rate data stream at the transmitter. At the receiver the high rate data stream is decoded back into the low rate data stream.
Establishment of protocol between a remote unit and a base unit prior to the communication session is well known in the modem communication art. Thus, for example, in packet communications, prior to the communication session in accordance with the X.25 protocol the remote unit and the base unit negotiate the packet size. In addition, in the modem communication art, modems having different transmission rate capabilities determine, prior to the communication session, the fastest speed at which both units can accommodate one another.
In the prior art, it is known that the transmit power can be adjusted based on a priori knowledge of the transmitted power and the expected received power by the other side. However, this prior art is normally limited in that it assumes a fixed channel attenuation.
In the prior art, it is also known to command adjust the dynamic power control by using a feedback loop. However, for a TDMA system, the delay that is composed of the measuring time, the transmission time and the application time results in large degradation. Also, the amount of message rate that needs to be allocated for power control is sometimes large which results in a loss of capacity.